Armatukje reoutting tool



P 5, 1944. w. H. RHINDRESS 2,357,765

ARMATURE RECUTTING TOOL v Filed Aug. 2, 1940 2 Sheets-Sheet l F'lE1.1. FIE.Z.

I I INVENTOR v I 6 Mm I Sept. 5, 1944. w. H. RHINDRESS 2,357,755

' ARMATURE RECUTTING TOOL Filed Aug. 2, 1940 2 Sheets-Sheet 2 was. A

.D-4 34 FIEJQ i 5: 44

" 6/ i 1' I mvzumn 45", BY ZZLz m.m 55 36 5 Patented Sept. 5, 1944 UNITED STATES 'FF ICE 2,357,765 ARMATURE REOUTTING 1 061. Walter H. lthindress, Braintre', Mass. Application August 2, 1940, Serial No. 349,905

9 Claims". (01. '82-' 4) This invention relates to tools for cutting or recutting such armatures as are carried "by a a suflicient force to be cut but to permit the tool to beeasily operated by hand and at the same time to cause the armature to move axially a little for each cut. The revolving and feeding can be accomplished by using a very fine thread' but when the spiral cut is finished and the parts must be returned to their original position to receive another armature, the fine thread requires a great many turns, meaning delay and extra Work. Besides this, a fine thread is not strong and such a tool requires strength.

This tool is so arranged that while the armature is movingagainst the cutter and being cut, i'tsaxial progress is slow, but when it is desired to return the parts to their original position, it'canbe done very quickly by a relatively few turns of a feed screw having a relatively coarse thread. I I I The turning of the armature for the cutting is steady, but the axial feed is intermittent while cutting but steady on return.

'I am aware that an armature on a shaft, can be out by holding the shaft in a lathe chuck on a horizontal axis and by either moving a cutter along it while the armature is being revolved or feeding the armature toward or along a s'tation-; ary cutter, I

I am aware that in patent to Burrows and to myself dated January 23, 1940, No. 2,187,874, the armature is held in a vice while a hand tool is fixed to the armature shaft and the tool with a cutter is revolved and moved forward by a hand wheel. With any construction where either the tool or the armature is suspended on a horizontal axis, there is a tendency to sag and when either is revolved against a cutter, the cut is not a true circle and" with a direct hand drive with a hand t-oohthere: is a tendency to bear down at certain parts of the rotation and this also prevents the cut from being a true circle. There is also a limit to the effective working pressure which can be manually applied and as this is a handtool for. cutting metal, there is a limit to the width and depth; of the out which can be made without-the usepf power.

w t this tool, the armature and shaft are carried vertically thus avoiding any tendency to sag, and the pressure is applied by a hand wheel on a horizontalaxis which prevents sagging and unevenpressure on the, re'volvingarmature which is being cut. The cuttin element is stationary .5 and although the "reed screw has a relatively coarse pitch, the; actual movement of the armae ture is intermittent; the, principal part oithe, cutting being annular rather than spiral. This permits the use of a strong, coarse feed screw to cut a thin or narrowchip and of course such a chip can be cut with .less manual effort than a thick wide chip.

In-the drawings I Fig. '1 is an isometric view or my tool in the upright position, as-itis preferably used, and With thearmature-and{shaftas they appear at the end of a cut. v I

Fig. 2' is. anisometric view similar to Fig. l but from a; .difierentidirectionand with the parts as they appear at thebeginning of a cut.

Fig. -3,,is.a vertical sectional view as on the" line 3-3 of Fig. .4.

Fig. 4 is aplaniv-iewof the tool without the armature and; shaft. .:-Fig. 5 is .a horizontal-sectional view as on'the line5-'-5 of-Fig. 3.

Fig-e6 is .a horlzontalsectional view as on the line 6.-.6 of Fig. 3. v I

Fig. 7 is a side elevationof a preferred :type of cutter. assembly. in .one position and Fig. 8 is a" similar view showing it in ;a difierent.p0si-' tion.

Fig. 9 is: aidetailview .of another cutter as-' sembly.

Fig. :10'isan enlarged elevation of the spindle with the c'ollet -anddrawbar, removed from the nfachine, withparts broken away to show the construction; I

In the drawings, A represents the body of the device fro'mi which extends a projection 39 'by which the wh'oleitool can be held in the jaws of a vice V. As shown, it is held vertically.

Extending preferably vertically through body A is .aspin'dl'e hole. 40 for the tubular spindle B. Extending lengthwiseon' the outside of' this spindleB is aturning slot into :which enters a turning pin 41 which extends; inward from the pinion'J driven .by drive gear K and a handleiL: 'Omthe. outside atoneendof-spindl B isthe annular feed .groov'e l in which are one" ortwo pins; such as '61,- .which engage a Geneva motion to bedescribed: i

..Slidable in' thehoie uzin spihale Bis a toilet 0; having atthe top" aaspl'it end30" to receive the shaft-3l of the armature 32' and provided with threads 33 at the other end. Dra'wbar D has threads 34 which engage with the threads 33 on the collet C and has an integral collar 35 which extends over and rests against the bottom outside end 45 of spindle B. This collar 35 has turning slots 36, 36 by which it and drawbar D can be turned or held stationary as by a pin P. When not so held, collet C and drawbar D move with spindle B, but when held by pin P, threads 33 and 34 cause them to move towards or away from each other depending on the direction in which L, K, J and B are turned to engage and hold or release the shaft 3| of the armature 32.

There is a cutting assembly attached to the body A including a cutter H, rocker bar I and adjusting screw G by which the depth of the cut on the armature can be regulated.

The commutator 2|] of armature R is carried by shaft 3| and includes metal strips 2|, 2|and insulation 22, 22.

Cutter holding block 9|I'is slidable in body A and can be adjusted by set screws 93, 93.

'Pin 38 in spindle B enters keyway 3'! in collet C. Rocker bar I and cutter H extend sufiiciently up and out beyond the end of spindle B so that the armature can be started at the high point shown in Fig. 2 and brought down to the dotted position, thereby allowing the cutter to cut over the entire curved surface.

The slow cutting, feeding and quick return are accomplished by a feed screw which is revoluble, but not axially movable, .in body A and is turnable by a small hand crank 60. It is held in place by a collar 66 and nut N.

M' represents a combination feed gear and Geneva motion which is threaded on the inside 62 to engage the outside threads 63 on the feed screw 0. The Geneva wheel 64 fits into the annular feed groove 44 on the spindle B in. such a way that itis engaged by one or more of the Geneva pins 6|, as the spindle B is turned by the pin 41 carried by the pinion J.

As the combination feed gear and Geneva motion are turned, they are carried along the feed screw- O'and carry with them the spindle B, collet C, drawbar D, armature R and its shaft 3|. The axial movement is intermittent as the Geneva pin 6|, operates on the Geneva wheel, and the cutting is not a continuous'spiral.

. When the cutting of one armature has been accomplished, the crank 60 of the feed screw 0 is turned in the opposite direction and as the threads on the feed-screw are of a relatively coarse pitch, each turn moves the spindle B and its accompanying parts a ;very much greater distance back than thedistance in the opposite direction producedby each tum'of the handle L. This ratio can be changed to make it greater or less.-

Parts B, C and D move together except when pin P is held i-n'a slot 36 when, gripping and releasing a shaftj3l'. 'T 1 As' a convenient arrangementfor seizing and holding the shaft 3| of an; armature R, I'use a pin P normally kept out of turning slots 36, 36. When it is desirable to open or close the end 30 of the collet C, this pin P is pressed in to engage a slot 36 and this stops drawbar D from turning. Therefore, when handle L, gear K and pinion J are turned, spindle B and the Geneva motion M are turned thus moving spindle B forward or back thereby opening or closing the split end 300i collet ,C on the shaft 3|. First the collet is opened, then the shaft is inserted, then the colletis closed and then pin Pis allowed'to spring out whereupon the parts are ready to operate.

When the pin P does not engage either slot 36, the turning of handle L moves the spindle B and collet C forward or back slowly as these advance only when the Geneva wheel 64 is moved by a pin 6|. As shown, it requires five engagements of a pin 6| to advance the parts one thread on feed screw 0. On the other hand, when turning feed screw 0 by crank 60, the action is five times as rapid and the spindle and collet can be moved forward or back very quickly.

In practice, after the armature and shaft have been gripped, these parts are advanced to the forward position by turning crank 60 and are drawn back by turning the handle L.

One advantage of this construction is that when the Geneva motion has been carried back as far as the collar 66 on the feed screw 0, all the parts revolve together thus automatically stopping the device and preventing cutting too far on the armature commutator.

Nut N overlaps collar 35 and holds drawbar D up allowing collet C to turn and mOVe up on pin 38, when pin P engages a slot 36, to open split end 30.

In repairing armature commutators in addition to turning the curved surface down to a true cylinder, it is often necessary or desirable to undercut the isinglass or other insulation 22, 22 between the metal strips 2|, 2|, and it is desirable that this should be done accurately and while the armature is held in position so that the cuts will be parallel with the axis.

This is conveniently doneby using a. special combination cutting assembly such as is shown at Tin Figs. '7 and 8. This can be used with a cutter such as H for turning down the armature or for undercutting by substituting for H, a cutter 14 of a different shape.

A block 10, preferably, with a straight direction groove 12 is slidable in ways 1 I, II, in a direction exactly parallel with the axis of the work. Block I0 can be moved parallel with the axis or clamped in position by the set screws, 13, 13

Through block 10 is a rectangular guideway for a cutter carrying slide bar 8| which fits snugly on each side but has clearance at the top and bottom. This slide bar 8| has a recess 82 in which a cutter like 14 or like H can be clamped ened so as to hold the slide bar 8| rigidly in' place when the commutator face is being turned.

When undercutting, this set screw 16 is loosened, allowing the cutter carrying slide bar 8| to move to and from the axis of the armature so that by pressing on the handle 86 on the forward stroke, the cutter 14 will cut and by lifting handle 86 with the link 88 as shown in Fig. 8, the cutter l4- can be adjusted by means of a collar 94, screws 'and 96 and'nut 91.

There is also a set' 'I- claim: I p

1. In a machine for cutting commutators of armatures which are provided with a shaft; the combination of a body, including means to hold the body stationary and a spindle bearing hole; with a tubular spindle axially slidable in the spindle bearing hole, such spindle being formed with an outside longitudinal spindle turning slot and an annular feed groove in which is a Geneva pin;

spindle driving means including a turning pin in the spindle turning slot; work holding means extending through the spindle including a split collet with jaws at one end to receive and hold the armature shaft and at the other end a drawbar threaded to the collet to open and close such jaws;

a spring actuated pin to stop the drawbar from turning with the collet; a Geneva wheel which enters the feed groove in the spindle and engages the Geneva pin therein and is provided with a threaded feed screw passage; a feed screw with I an outside handle revoluble in the body and which passes through and engages the threads of the Geneva wheel feed screw passage; and a cutter assembly adjustably attached to the body in position to engage an armature commutator as it is revolved and moved by the spindle and to be moved along the surface of the commutator parallel with its axis.

2. In a machine for cutting commutators of armatures which are provided with a shaft; the combination of a body, including means to hold the body stationary and a spindle bearing hole; with a tubular spindle axially slidable in the spindle bearing hole, such spindle being formed with an outside longitudinal spindle turning slot and an annular feed groove in which is a Geneva pin; spindle driving means including a turning pin in the spindle turning slot; work holding means extending through the spindle including a split collet with'jaws at one end to receive and hold the armature shaft and at the other end a drawbar threaded to the collet to open and close such jaws; a spring actuated pin to stop the drawbar from turning with the collet; a Geneva Wheel which enters the feed groove in the spindle and engages the Geneva pin therein and is provided with a threaded feed screw passage; a feed screw with an outside handle revoluble in the body and which passes through and engages the threads of the Geneva wheel feed screw passage; and a cutter assembly adjustably attached to the body in position to engage an armature commutator as it is revolved and moved by the spindle.

3. In a machine for cutting commutators of armatures which are provided with a shaft; the combination of a body, including means to hold the body stationary and a spindle bearing hole; with a tubular spindle axially slidable in the spindle bearing hole, such spindle being formed with an outside longitudinal spindle turning slot and an annular feed groove in which is a Geneva pin; spindle driving means including a turning pin in the spindle turning slot; work holding means carried by the spindle to receive and hold the armature shaft; a Geneva wheel which enters the feed groove in the spindle and engages the Genevapin therein and is provided with a threaded feed screw passage; a feed screw which passes through and engages the threads of the Geneva wheel feed screw passage; and a cutter assembly adjustably attached to the body in position to engage an armature commutator as it is revolved and moved by the spindle and to be moved along the surface of the commutator parallel with its axis.

4. In a machine for cutting commutators of armatures which are provided with a shaft; the combination of a body including means to hold the body stationary, a spindle bearing hole and a guidewayparallel with the axis of the spindle bearing hole; with a tubular spindle revolubleand axially'movable with a feed gear; insuch bearing hole; manually operable spindle driving means for turning the spindle rapidly and moving it axially slowly with the feed gear; other manu-,

ally operable means including a feed screw for the feed gear to move the spindle axially rapidly; work holding means carried by the spindle torece'ive and hold the armature shaft; and a cutter holding block slidable in the guideway parallel with the axis of the spindle, and means to hold the block in-fixed position the guideway.

' 5. In a machine for cutting commutators of armatures which are provided with asha-ft; the combination of a body including means to hold the body stationary, a spindle bearing hole and a guideway parallel 'With' the axisof the spindle bearing hole; with a spindle revoluble and axial-1y movable with'a feed gear, in such bearing hole; spindle driving means for turning the spindle and moving it axially with the feed gear; other means including a feed screw for the feed gear to move the spindle axially; work holding mean carried by the spindle to receive and hold the armature shaft; and a cutter holding block slidable in the guideway parallel with the axis of the spindle, and means to hold the block in fixed position in the guideway.

6. In a machine for cutting commutators of armatures which are-provided with a shaft; the combination of a body including means to hold the body stationary, and a spindle bearing hole; with a spindle revoluble and axially m'ovable with a feed gear, in such bearing hole; spindle driving means for turning the spindle and moving it axially with the feed gear; other mean including a feed screw for the feed gear to move the spindle axially; work holding means carried by the spindle to receive and hold the armature shaft; and a cutter holding block carried by the body.

'7. In a tool for cutting commutators of armatures which are provided with a shaft; the combination of a body including means to hold the body stationary in a vertical position, a spindle bearing hole and a cutter holding guideway parallel with the axis of the spindle bearing hole both in a vertical position; with a tubular spindle revoluble and axially movable in such spindle bearing hole; work holding means carried-by the spindle to receive and to hold the armature shaft; manually operable means for turning the spindle; a manually operable feed screw turnable in the body and having outside threads; means including a feed gear threaded on the inside to engage the outside threads on the feed screw; connections between the feed gear and the spindle for moving the feed gear and spindle when the feed screw is turned and for turning the feed gear intermittently on the feed screw when the spindle is turned whereby the feed gear is revolved more slowly than the spindle as the spindle is being turned and whereby the feed gear and the spindle can be retracted slowly by turning in fixed position in the cutter holding guideway.

8. In a toolforcutting commutators of armatures which are provided with a shaft; the combination'of a body including means to hold the body stationary, a spindle bearing hole and a cutter holding guideway parallel with the axis of the spindle bearing hole; with 'a tubular spindle revolub'le and axially movable in such spindle bearing hole; work holding means carried by the spindle to receive and to hold the armature shaft; manually operable means forturning the spindle; a manually operable feed screw turnable in the body and having outside threads; means including a feed gear threaded on the inside to engage the outside threads on the feed screw; connections'between the feed gear and the spindle for moving the feed gear and Spindle when the feed screw is turned and for turning the feed-gear on the feed screw when the spindle is turned whereby the feed gear is revolved more slowly than the spindle as the spindle is being turned and whereby the feed gear and the spindle can be retracted slowly by turning the spindle and can be advanced rapidly by turning the feed screw; and a cutter holding block slidable in the guidewayparallel with the axis of the spindle and ineluding means to hold the block in fixed position in the cutter holding guideway.

9. In a tool for cutting commutators of armatures which are provided with a shaft; the combination of a body including means to hold the body stationary and a spindle bearing hole; with a tubular spindle revoluble and axially movable in such spindle bearing hole; work holding means carried by the spindle to receive and to hold the armature shaft; manually operable means for turning the spindle; a manually operable feed screw turnable in the body and having outside threads; means including a feed gear threaded on the inside to engage the outside threads on the feed screw; and connections between the feed gear and the spindle for moving the feed gear and spindle when the feed screw is turned and for turning the feed gear on the feed screw when the spindle is turned whereby the feed gear is revolved more slowly than the spindle as the spindle is being turned and whereby the feed gear and the spindle can be retracted slowly by turning the spindle and can be advanced rapidly by turning the feed screw.

WALTER H. .RHINDRESS. 

